A story about a family of witches cannot be told without at least a little bit of flying, broomstick or no

A story about a family of witches cannot be told without at least
a little bit of flying, broomstick or no. Griffin Dunne brought
in visual effects supervisor John Scheele to get the ladies off
the ground.

The sequence had been carefully planned by Scheele and SFX coordinator
Burt Dalton. Initially, Scheele extensively pre-visualized the
sequence for director Dunne using a CGI simulation of the scene
with 3-D figures.

"This gave us a very tight road map of how to shoot the green-screen
performances of the actors," explains Scheele. Once the scene
had been fully mapped out, Burton then designed an elaborate rig
which enabled all six of the actors to fly at the same time.

Although a green screen would be utilized in the scene (with that
portion being staged in a San Juan county fairground building),
the actors themselves still had to levitate off the roof of the
house. Dressed in cliched witches' costumes, Bullock, Kidman,
Wiest, Channing, Evan Rachel Wood and Alexandra Artrip teetered
on the widow's walk of the house more than 25 feet from
the ground. As the three-generational family of witches (wearing
intricate harnesses concealed beneath their costumes) swung out
into the air, director Dunne played recorded dance music for the
women to "groove" to.

The visual effects weren't limited to the art of flying. John
Scheele was also responsible for the creation of Jimmy's ghost
and his possession of Gillian, which involved some very complicated
and newly created processes.

"When we had our first visual effects meeting," explains
Scheele, "both Robin Standefer and I came to the table with
the same concept-that of basing the look of Jimmy's ghost on the
style of the daguerreotype photographs of the 1850s. Those haunting
pictures of dead ancestors and fallen soldiers really inspired
us to create something new based on an archaic photographic process.
The daguerreotype process is more of a proto form of photography
and it looks more like a laser holograph than a photograph. It
is like a dark mirrored surface that, when moved in a certain
way in the sunlight, makes the image visible."

In order to re-create that look, Scheele researched the CGI tools
that were currently available and found them lacking. "J.
Riddle and the team over at Cinesite immediately began developing
new software. They created what they call an optical flow software,
which analyzes and predicts the motion of a figure as it moves
across the screen. It creates a distortion of that image that
looks kind of like a wave form moving over the figure. Imagine
the momentum of someone walking and, as they stop, the image of
their movement crests and swarms over them. In movement, the image
of Jimmy's spirit is unfocused. But if he stays very still, the
focus of his image would collapse and become relatively sharp."

The possession of Gillian by Jimmy also required an innovative
approach. "Jimmy is drawn back to Gillian," continues
Scheele. "He seeks to merge back with her and even into her.
There are a couple of remarkable scenes where we are working with
both the real photographic images of Nicole and Goran and cyber
scans, which produce 3-D images of their faces. At certain times
we can see Jimmy's face rise up inside Gillian's. He is literally
lurking inside her. It's like looking at him through amniotic
fluid. At first you see him indistinctly, but as he rises up to
the surface of her face he takes it over-her eyes become his eyes."